SEA BOTTOM LANDSLIDE IN THE SHENHU AREA ON THE NORTH MARGIN OF SOUTH CHINA SEA AND TRIGGERING MECHANISMS

Submarine landslide occurs widely on the continental slope.It is one of the major forces affecting the morphology of continental margin,and one of the major mechanisms to transport sediments from the shallow water to the deep basin.Episodic large-scale submarine landslide may trigger tsunami and cause huge losses in property and human life in coastal areas.Therefore,it is of significance to investigate the distribution,source,mechanism and evolution of submarine landslides.The South China Sea is of a passive continental margin,characterized by rifted and rotated fault blocks and steep continental slope.Therefore,there are often submarine sliding.Typical geomorphologic features of a submarine landslide include an arcuate headscarp,a sharp valley with sub-parallel sidewalls and slumped material at the base of the valley sometimes.Some slumps have been discovered in the Shenhu area on the north margin of South China Sea with 3D seismic data.In this paper,we discussed the triggering mechanism of sea bottom slumping in the study area in addition to morphological features and seismic identification criteria.